Hopefully you have this sample:
samples/raytrace/mtlstudy.max

Open that up, delete everything except one of the marbles. If you take that marble and make it non-smooth and reduce the number of segments you get a nice, transparent gem.

I can''t find anywhere to set up caustics though. I know Pov-Ray does them nicely (this is where when you have a glass of water on a table, it focuses the light into a bright spot on the table). The mtlstudy example fakes it by using a spot light and shadow which quickly fails if you stretch the marble into anything but a sphere close to the table.

To make that material, you have to go to the material editor and in the type field, choose Raytrace. Copy the other parameters from the marble''s material and you have a pretty good looking transparent material with refraction, controllable by changing the Index of Refraction value near the top of the material. 1.0 gives a nice balloon, 3.0 totally flips what you see inside the object.

Hope this helps!



-ns-